Purpose: This study sought to investigate the attitudes of Vietnamese undergraduate business students towards English-Medium Instruction (EMI) courses. Design/methodology/approach: Data were collected through purposive sampling using structured questionnaires, resulting in a dataset comprising 291 responses. This study employs a combination of Importance--Performance Analysis (IPA) and structural equation modeling (SEM) to evaluate students' perceptions of effectiveness of EMI courses, their satisfaction and loyalty. Findings: The study's findings revealed a noteworthy pattern: students assigned higher levels of importance to various aspects of EMI courses than the actual performance levels of these elements. Additionally, the analysis identified specific attributes that fell into different IPA quadrants, shedding light on their relative significance. Notably, the students placed their teachers' professional expertise and English proficiency in the "keep up the good work" quadrant, indicating the strengths of these attributes. In contrast, learning assessment techniques, course learning materials and electronic teaching platforms were situated in the "concentrate here" quadrant, implying room for improvement in these areas. Furthermore, it was observed that attributes falling within the "keep up the good work" quadrant had a positive effect on students' overall satisfaction and loyalty, while other characteristics did not significantly contribute to predicting these outcomes. Originality/value: Based on these findings, the study offers recommendations for educational institutions and educators concerning the planning and implementation of EMI courses.